Gas turbine plant



. Oct. 13, 1942. A. mfsHoLM` GA TURBINE PLANT I Y 3 Sheets-511eet l Original Filed May l2, v1938 Sx di l mw ,mmf Il n. E NQ m m,

oct. 1-3, l1942, A LYSHOLM i Re 22,201 'GASATURBINE PLANT originl Filed May 12, 1938 s Sheets-sheet 2 /765fnerm/G Marce Oct. 13,v 1942. -A. L YsHoLM R@ 22,201

GAS TURBINE PLANT Original Filed May 12, 195,58 I5 Sheets-Sheet 3A Sm mn. im m., h

w I OR ATTORN'EY ditions.

.the turbines.

RessuedOct. 13, 1942 I Re. A22,201

GAS TURBINE PLANT Alf Lysholm, Stockholm, Sweden, assigner, byu

mesne assignments, to Jarvis C. Marble, New York, N. Y., Leslie M. Merrill, Westfield, N. J., and Percy H. Batten, Bacine,Wis., as trustees original No. 2,238,905, dated April zz. 1941, serial' No. 207,457, May 12, 1938. Application for reissue April 21, 1942, Serial No. 439,956.

Great Britain May 14, 1937 21 Claims. (Cl. 60-41) The presentinvention relates to gas turbine plants of the continuous combustion type comprising a plurality of turbines or turbine stages and a 'plurality of heating means for heating the motive fluid to be expanded in the turbines. In order to obtain a. simple control of such gas turbine plants, it has proved suitable, in designing the gas turbine system, to make endeavours to have the different parts of the plant at variations in loadadjust themselves automatically so that under normal conditions the change of the fuel supply to a single heating chamber or the like will be sufficient to adjust the useful power 'as well as the power required for the compression of the combustion air inv accordance with vary ing operating conditions. I

However, such simple control is not always possible. It is one of the objects of the invention to provide in plants in which a single control would n'ot be sufficient, simple controlling means to be easily adapted to varying load con- Another object of the invention is to provide means whereby it will be possible to supply heat to the variousl heating means independently of one another. A further object of the invention is to avoid as far as possible the use of control valves for the supply of motive fluid to Due to the large volumes of the motive fluid and the high temperatures of the same such control valves are very expensive and cause considerable losses of pressure.

For a bettery understanding of the nature of the present'invention and the advantages to be de# rived from its use, reference is had to the accompanying drawings forming a parte! this specifi-` cation.

In the drawingsf Fig.V 1 shows more or less diagrammatically a gas turbine plant for driving an electrical generator, some of the parts of the plant being shown in section; l l

Fig. 2 is a. gas turbine plant adapted for marine propulsion and comprising four gas turbines coupled in series, each of the turbines being provided with heating means for the motive fluid;

Fig. 3 is a diagram illustrating the operation of the fuel pumps of the gas turbine plant shown in Fig. 2; and

Fig. 4 shows a gas turbine plant in which gas ls produced in gas generators associated with r separate fuel pump the fuel supplying characA teristic of which is independent of that of the other. fuel pumps or is individually adjustable. Assuming a plurality of such fuel pumps running at the same speed because of a common drive,

said fuel pumps may, in accordance withthe` present invention, be varied separately and independently as to their fuel supplying characteristics, that is, any influence due to controlling movements should act on each pump in a difierent way so that thevsupply of fuel by one pump may be changed in a manner different from the change of the fuel supply of other pumps. By the provision of heat supplying devices having individual heat supplying] characteristics it is possible accurately to adjust the supply of heat to theseveral heating devices vand to`have the several heat supplying devices respond in different ways to the action of the controlling member.

It is, for instance, `possible to actuate such heat supplying devices, such as fuel p umps, by a common centrifugal governor, each individual pump responding, however, in different manner to the common controlling impulse. There is a further possibility of adjusting the characteristic of each heat supplying device in a manner such that all heat supplying devices or part of them will respond to the action of the control member throughout the whole range of loador only part thereof. The heat supplying devices may be in the form of fuel pumps, gas generators, heat exchangers and the like apparatus for imparting heat to the motive fluid.

In the embodiment shown in Fig. l, fuel pumps Vare used for supplying metered quantities of fuel to separate combustion chambers in which the fuel is burnt with air compressed in a compressor driven by part of the gas turbines. lll designates a high pressure gas turbine mounted on ashaft l2 which by means of a coupling Il is connected with the shaft I6 of a'low pressure turbine I8. Another low pressure turbine 2li coupled in parallel with the turbine IB is mounted on a shaft 22 which also carries an electrical generator 24, pump'actuating cams 26 andv 28,

surecompressor 36. The compressors are of the rotary screw type having a casing and rotors 38, 40 and I2, 44 respectively provided with intermeshlng lobes cooperating within the casing to provide compression spaces of variable volume. The Outlet 0f the low pressure compressor is connected to the linlet of the high pressure compressor by means of a conduit 46. A` conduit 48 connects the discharge side of the high pressure compressor` to a combustion chamber 50 which communicateslwith vthe inlet of the high pressure turbine I through a conduit 52. The ex,- haust conduit 54 of the high pressure' turbine is connected to a second combustion chamber. or reheating chamber 56 which through conduits 58 and 60 is in communication with the inletsI 10 indicates a fuel tank from which fuel, such as oil, issupplied to the combustion chambers by means of two displacement pumps 'l2 and 14, diagrammatically indicated ln the drawings and having suction pipes 16, 18, 'inlet valves 80, `82, outletvalves 84, 86, and discharge conduits 88, 80, respectively. The plunger 82 of the fuel pump 12 ls adapted to be actuated by the rotating cam V26 againstthe action of a helical spring 84 resting against an annular member 96-s`ecured tov the casing of the pump and against an annular projection 98 integral with the plunger. While the. lower position of the plunger 92 is determined by the cam 26 and the length of the portion |'00 of the plunger cooperating with the said cam,

said lower position being definitely determined bY` the construction of the said parts, the uppermost position of the plunger and, consequently, the stroke of the pumpis .determined by the position of a lever |02 pivoted at |04 and having an abutlever |02 is controlled by the governor 32 by` means of a lever |08 pivoted at l I0 and by means of a rod ||2 linked to the levers |00 and |02, as

link |28. The length of the rod |22 is variable by means of a turnbuckle |30.

Between the inlet and the outlet o'f the low pressure compressor 34 the casing has an aper ture |32 to which there is connected a conduit `|34 normallyclosed by a `valve |36 which is held against its seat under the action of a spring |38 resting against a. disk |40 secured to the stem |42 of the valve. A rod |44 carried in a suitable the ycombustion of fuelsupplied to the combustion chamber by the pump 12 and the fuel supply conduit 06. The Vheated motive fluid is admltted tothe high Pressure turbine I0 in which it produces power by decrease in pressure and temperature. The exhaust gases of the high pressure turbine are reheated in the reheating chamber 56 by admission thereto' of fuel supplied by the fuel pump 14 and the conduit 00, The reheated motive fluid is then suppliedI through the conduits 50 and .60 t0 the low pressure turbines I8 and .20 respectively. As will be seen, the

` power produced by the turbines l0 andV I8 is utilevers |02 and ||8 respectively are in their uppermost positions so that the pumps will work with the greatest stroke of their plungers and will supply the maximum quantities of fuel to the combustion chambers 60 and 56 respectively. In the lowermost position of the governor sleeve |58 the rod |44 is in its left-hand end position in which the distance between the right-hand end of the rod and the valve stem |42 hasits maximum value. The valve |36 is thus held in closed position under the influence of `the spring |38.

If the load on the plant decreases, the governor sleeve |58 will move upwards, and this movement is transmitted by the linkages cooperating with the lever |08 to the levers |02 and ||8 which will be turned ln an anti-clockwise direction so that their abutments |06 and |64 will be moved downwards and thereby decrease the upward stroke of the plungers 02 and 4. As a consequence thereof, the pumps 12 and 14 will supply. a'decreased quantity of `fuel corresponding to the decrease in load so that the speed of the useful power turbine 20 `will be maintained substantially constant. Due to the diminished supply of fuel, the compressor turbines I0 and I0 willl impart a correspondingly reduced output to the compressors. so that the compressor aggregate together with the last-named turbines will rotate at a reduced speed and produce a decreased quantity of compressed air corresponding to the decrease in fuel and to the new load condition.

bearing |46 is arranged `in alignment with the stem |42 and is normally held at al short distance from the stem under the inuence of the governor 32 to which ,the rod |44 is connected by a' suitable linkage consisting of a lever |4|| pivoted at |50, a link |52 and alever |54 pivoted at |56 and :connected to the sleeve |58 of the governor.

In operation, air is drawn into the low pressure compressor as indicated by the arrows |60 and |62. After having been compressed therein the air ows through the conduit 46 into the high pressure compressor 36 and ls conducted after final compression through the conduit 48 into the 4 combustion chamber 50 in which it is heated by,

Upon the upward movement of the governor sleeve |58 the rod |44 will be moved towards the right. Thereby, the distance between the adjacent ends of the rod |44 and the valve stem |42 will be more or less reduced, but this distance will be still so great that the valve stem will not be actuated by therod, and the valve |36 will thus he maintained in closed position.

As will be seen from the drawings, the leverage of the lever |08 with respect to its`fulcrum ||0 is dierent from the leverage of the lever |24, the arrangement being such that upon a certain upward movement of the governor sleeve |58 the downward movement of the lever abutment |84 will be greater than the downward movement of the lever abutment |08.` From this it follows that the pumps, although they are influenced by a common governor, will be controlled independently of eachother as to the quantity of fuel supplied by them. Thus, upon a certain increase of the speed of the useful power turbine 20 the decrease of .the quantity of fuel supplied by the pumpv14 will be greater `than the decrease of the quantity of fuel supplied by the pump 12. It will 19,0, |92, and |94. turbines |10 and |12 drive, by means of a suitable gearing |96, |98, 200, the propeller 202 of a' be obvious that the ratio between the decreases of the fuel quantities supplied by the pumps can be altered to any desired rate by suitably adjusting the lengths of the parts-of the linkage actuating the levers |02 and ||8 or by varying the places of the fulcrums ||0 and |26, or by varying the lengths of the connecting rod |22 byV means of the turnbuckle |30. l

Since the reduction of the stroke of the plunger ||4 upon decrease in load is `greater than the reduction of 'the stroke of the plunger 92, the projection ||6.of the plunger ||4 will be lowered at a certain low load to such an extent, thatl the plunger rod |66 will be moved downwards ou: of the path-of the cam 28 so that the pump 14will be entirely put out of operation. In this case,

fuel is supplied to the high pressure combustion chamber 50 only, and no reheating of the motive fluid takes place in the low pressure combustion chamber 56. A customary pilot burner not illustrated in the drawings is preferably arranged in the chamber 56 so that a new combustioncan be started therein immediately upon increase in load.

right that it engages the valve stem |42 and opens the valve |36 with the result that a por- At low loads the rod |44 is moved so far to the Y tion of the air drawn in by the low pressure comclosedand the starting motor 66 is put into operation. When the compressor aggregate is sufficiently speeded up to produce a certa-in quantity of compressed air, the valve 68 is opened and the turbine 20 will then be started by compressed air and operatethe fuel pumps so as to supply fuel to the combustion chambers.

The embodiment of the invention illustrated in Fig. 2 comprises four turbines |68, |10, |12, and |14 coupled in series and operating on separate shafts. The high pressure turbine |68 drives an intermediate pressure compressor |16, a high pressure compressor |18 and four cams |80, |82, |84, and |86 for actuating four fuel pumps |80, The intermediate pressure vessel. Each turbine is provided with a heating chamber 204, 206, 208, and 2 I0, respectively. The low pressure turbine |14 drives a low pressure compressor 2|2. 2|4'indicates a starting motor adapted to start up the compressors |16 and |18.

The air compressed in the low pressure compressor is supplied to the intermediate pressure compressor by means of a conduit 2|6. 2| 8 is a conduit for supplying air compressed in the intermediate pressure compressor to the inlet of the highpressure compressor. The finally compressed air passes through a conduit 220 to the high pressure combustion chamber 204 and thence through the conduit 222 to the inlet of the high pressure i turbine |68. The fuel pumps are constructed and operate in the same manner as described with reference to the fuel pumps 12 and 14 in the embodiment shown in Fig. l. They are connected to the respective combustion chambers by means of the fuel supply conduits 224, 226, 228, and 230- Control of the plant described is effected manually by means of a controlling device diagrammatically indicated by a control lever 232 which is pivoted at 234 and which acts upon the four fuel -pumps by means of a link 236 engaging four levers 238, 240, 242, and 244. These levers are linked to levers 246,y 248, 250, and y262, respectively, which are provided with abutting surfaces adapted to engage the respective plungers of the fuel pumps in the manner described with reference to the pumps shown in Fig. 1. The levers 23a-244 have different leverages such that upon displacement of the link 236 the turning movement of the lever 252 will be greater than that of the lever 250 and still greater than that of the llever 248, the movement of whichwill be greater than that of the lever 246.

The quantities of fuel supplied by the different pumps are illustrated in the diagram shown in Fig. 3, in which the abscissae indicate the load on the plant in percent and the ordinates represent amounts .of fuel supplied by the pumps. The lines 254, 256, 258, and 260 represent the amounts of fuel supplied by the pumps |88, |90, |92, and |94, respectively. At full load, all of the. pumps are supplying their maximum quantity of fuel. At a partial load a the fuel quantities will be produced, the reduction being greatest for the pump |94 which supplies fuel to the combustion chamber 2|0 operating at the lowest pressure. At a load .indicated at b the pump |94 is entirely put out of operation. Upon further decrease of the load down to c also the pump |92 comes toa rest. Between no load and the load d. only the pump |88 is in operation. I

Th'e low pressure turbine |14 is in operation at high loads only. In order to put this turbine out of operation, there is provided a by-pass conduit 262 between the combustion chamber 2|0 and the turbine |14. The by-pass conduit has a valve264which at high loads is maintained closed under the action of a spring 266. The valve 264 opening of the valve 264 the motive fluid` exhausted from the turbine |12 will be-discharged through the conduit 262 so that the low pressure turbine |14 will come to a rest. In order to simultaneously put the lcw pressure .compressor 2|2 out of operation, a valve 210, provided in a branch conduit 212 is opened .by a suitable linkage 214 actuated by the control lever 232 so that air will directly pass from the latmosphere through the conduits 212 and 2|6 to'the intermediate pressure compressor |16.

The gas turbine plant illustrated in Fig. 4 comprises two gas generators, one generator being provided forrthe high pressure turbine 216 and the other one for the low pressure turbine 218.

The gas generator for the high pressure turbine comprises a combustion chamber 280 in which fuel is burnt on a stoker 282. Fuel is supplied to the Stoker by means of a suppiyiconduit 284 provided with a rotatablesluice valve 286 operated by an electric motor diagrammatically indicated at 288. 290 designales an electric motor for driving the stoker 282. Below the stoker there is provided an ash chute 292 havingl a rotatable sluice valve 294. The lower portion of sluice Valve 308 operated by an electric motor 3| 0. A motor 312 drives the Stoker 304. ash chute 814 is provided below the stoker and has a rotatable `sluice valve 3I6. The lower portion of the combustion chamber is surrounded by a hollow space 3|8 which, through openings 320 and 322, communicates with the combustion chamber, 324 indicates an air compressor, 328 an electric/generator, 328 a starting motor, and

" result that a portion of the compressed air can 330 a gearing for driving a centrifugal governor The compressor 324 is` provided with a bleeder pipe 334 having a valve 336 operable by the governor 332 by means of a suitable linkage 338 in ysubstantially the same -manner as described with reference to the valve 13,6 shown in Fig. l, with the exception that in the present embodiment the valve 336 will be opened already at a little decrease of theload below full load.

This is ,necessary for` the following reasons.` In the present embodiment, the air compressor is directly connected to the electrical generator 326 vwhich is assur-nedA to be driven at substantially constant speed. Without control of the compresv sor by means'of the valve 336 the air quantity supplied to the gas generators would be constant at `all loads. This would result in a considerable decrease of temperature of the motive fluid'at low -loads so that the plant weuld operate at very poor partial load efliciencies.

Air compressediin the compressor 324 passes through the conduit'340 into the hollow spacel 296 surrounding the combustion chamber 280 and therefrom partly through the openings 300 to the zone of `combustion and partly through pa'ssfrom the hollow space ,296' directly to the highpressure turbine without taking part in the combustion.

Control of the llowV pressure gasgeneratoris I effected in'substantially the same manner as the control of the high pressure gas generator. However, instead of the load governor a thermostat 362 provided in the inlet conduit 348 of the low `pressure turbine `is used as an impulse for the control. yBy means 'f conduits 364, 366 and 368, the thermostat 362 acts on suitable bellows diagrammatically indicated at 310, 312 and 314 in such a way that upon increase of the tempera ture in the inlet conduit 343 thenspeed'of the motors 3l0and 3|2 will be reduced, the valve 360 will be more or less closed, and the valvie.

opened correspondingly. i

In the present'embodiment there are provided, in` addition to the normal control means, two safety controlling devices constructed in the form of thermostats. The one of these controlling devices has for its purpose to prevent undue rise of the temperature of the motive iluid in the inlet conduit 342 of the high pressure turbinel and is in the form ofa thermostat 380 wihch at a certain maximum temperature by'means of a bellows 382 opens a valve 384 disposed in a second by-pass conduit`386 and thereby causes the motive fluid to be cooled by air passing directly from the space 296 surrounding the combustion chamber. T'he other safety control device con- 816 arranged in a by-pass conduit 318 will be v sists of a thermostat 388 located in the exhaust and thence through the conduit 346 to the gas I generator ofthe low pressure turbine, in which the excess of air contained in the exhaust gases is utilized for burning the fuel supplied to the low pressure gas generator., The motive 'fluid produced therein passes through `a conduit 348 provided with a valve 350 to the low pressure turbine 218.

Control of the high pressure gas `generator is reduced so that the supply of fuel and the velocity.

of v-the stoker will be decreased. The governor 358 arrangedI in a bv-pass conduit 360. The lastnamed valves are mechanically interconnected to each other in such manner that.y at full load the `valve 344 is entirelyopened and thevalve 358 is closed. Upon decrease inload the valve 344 reduces the cross-sectional area, whereas the valve pipe 380'of the low pressure turbine and adapted upon rise ofthe temperature in the exhaust pipe to a certain maximum value to open a valve 390 by means of a bellows 392. The valve 330 is located in a by-pas's conduit 384 through which motive iluid not heated -in `the combustion chamber 302 can flow to the inlet of the low pressure turbine and thereby cool the heated motive iluid supplied through the conduit 348. Y f,

From the foregoing description, it will be evident that many specific different arrangements may be employed within the scope of the invention, and it is to -be understood that the invention includes all that falls within the scope of the appended claims.

What I claim is: l 1. In a gas turbine plant of the continuous combustion type, a plurality of'turbines, compressor means driven by at least one of said turbines and arranged to produce a variable quantity of motive fluid, a plurality of independent heating means arranged at least before part of said turbines, means for supplying motive fluid. from said compressor means to said heating means and to said turbines, and a plurality of independent positively metering heat supply means for supplying independent variable quanfurther actsrupon the valve 344 and upon a valve 358 is opened to a corresponding degree with the titles oi' heat to the several heating means.

2. In a gas turbine plant of the continuous combustion type, a plurality of turbines, compressor means driven by at least one of said turbines and arranged to produce a quantity of motive uid variable ink response to variations in the load on the plant, a plurality of independent heating means arranged at least before part of said turbines, means for supplying motive uid from said compressor means to said heating means and to said turbines, a plurality of indepedent positively metering heat supply` means for supplying fuel to the several heating means, and controlling means for independently controlling said heat supply means.

. 3. In a gas turbine plant of the continuous A combustion type, a plurality of turbines, compressor means driven by at least one'oi' said turbines and arranged to produce a quantity of ymotive uid variable in response tovvariatlons -in the load on the plant, a plurality of independent heating means arranged atleast beforepart I of'said turbines, means for 'supplying motive fluid from said compressor means to said heat-l ing means and to said turbines, a plurality of independent positively meteringl heat supply means for supplying fuel to the several heating :neans, and controlling means responsive to the load on the plant for independently controlling saidyheat supply means. o

4. In a gas turbine plant of the continuous combustion type, a plurality of turbines, compressor means driven by at least one of said turbines and arranged to produce a quantity of motive fluid variable in response to variations in the Vload on the plant, a plurality of independent heating means arranged at least before partof said turbines, means for supply-j..

ing motive fluid from said compressorlmeans tov said heating means and to said turbines, a plulrality of independent positively metering heat tion chambers arranged at least before a part I ofy said turbines, means fo; supplying motive tluld from said combustion chambers to said turbines, plunger pump means for supplying separate positive metered quantities of fuel to the Several combustion vchambers and governing means for varying in predetermined relation the amounts of the separately metered quantities of fuel supplied to different combustion chambers.

8.,In a gas turbine plant of the continuous combustion type, a plurality of turbines, at least one -compressor driven by at least one vof said f turbines and arranged to produce a variable quantity of motive liuid, a plurality of combusq tion chambers arranged at least before part of said turbines, means for supplying motive fluid from said compressor iso/said combustion chambers and to said turbines, a plurality of independent positively metering fuelY pumps for sup- -5. In a gas turbine plant of the continuous pressor means driven by at least one of said turbines and arranged to produce a quantity of motiveuid variable in response to variations in the load onY the plant, a plurality of independent heating means arranged at least before part of said turbines, means for supplying motive fluid from said compressor means to said heating'means and to said turbines, a plurality of independent positively metering heat s upply means for supplying fuel to the several heating means, and controlling means responsive to the load on the plant for independently controlling said-heat supply means and for decreasing the quantity of compressed motive fluid at a decrease in load.

6. In a gas turbine plant of the continuous combustion type, a plurality of turbines coupled in series, compressor means driven by at least one of said` turbines and arranged toproduce a Acombustion type, a plurality of turbines, complying fuel to the several combustion chambers, and controlling means responsive to the load on the plant for independently. controlling the amount of fuel supplied by said pumps;

9. In a gas turbine plant of the continuous combustion type, a plurality of turbines, at least one compressor driven by at least one of .said turbines and arranged to produce a variable quantity of motive fluid', .a plurality of combustion chambersl arranged at least before partl of said turbines, means for supplying motive fluid from said compressor to said combustion chambers and to said turbines, a plurality of independent positively metering fuel pumps for supplying `fuel to the several combustion chambers,

and governing means responsive to the variations Y in load on the plant for positively varying the effective delivery strokeI of each of said pumps by a separate predetermined amount for each pump.

'10. In a gas turbine plant of the continuous combustion type, a plurality of turbines coupled in series, at least one compressor driven by at least one of said turbines and arranged to produce a variable quantity of motive fluid, a plurality of combustion chambers arranged at least before part of said turbines, means for supplying motive fluid from said compressor to said combustion chambers and to said turbines, a plurality of independent po-sitively metering fuel pumps for supplying fuel to the several combustion chambers, and controlling means responsive to the loadA on the plant for varying the stroke of said pumps such that upon decrease in load the [stroke of a pump supplying fuel toa low presquantity of motive fluidvariable in response to` variations in the load on` the plant, a plurality of independent heating means arranged at least before part of said turbines, means for supplying motive fluid from said compressormeans to said heating means and to said turbines, a plurality of independent positively metering heat supply means for supplying fuel to the several heating means, controlling means responsive to the load on the plant for controlling the first heat supply means in the series, and controlling means responsive to the temperature of the heated motive fluid for controlling the last heat supply means in the series.

7. In a gas turbine plant ofthe continuous combustion type, a plurality of turbines, at least one compressor driven by at least one of said turbines and arranged to produce a variable quantity of motive fluid, a plurality of combussure combustion chamber is decreased more than the stroke of a pump supplying fuel to a high pressure combustion chamber.

11. In a gas turbine plant of the-continuous combustion type, a plurality of turbines, at least one compressor driven by at least one of said turbines and arranged to produce a, variable quantity of motive fluid, a plurality of combustion chambers arranged at least before part of said turbines, means for 'supplying motive fluid from said compressor to said combustion chambers and tosaid turbines, a plurality of independent positively metering fuel pumps for supplying fuel to the several combustion chambers,

governing means responsive to the variations in load on the plant for positively varying the effective ydelivery strolre of each of saidpumps. by asaparate predetermined amount for each pump,

and means for changing the relationship of the' tion of load on the plant.

12. In a gas turbine plant of 4the continuous combustion type, a plurality of turbines, at least one compressor driven by at least one of said turbines and'arranged Vto produce a variable quantity of motive fluid, a plurality of combustion chambers arranged at least before part of said means and to said turbines, a plurality of lnturblnes, means .for supplying motive. fluid from4 said compressor to said combustion chambersv and to said turbines, a plurality. of independent positively metering fuel pumps for supplying fuel to the several combustion chambers, and governing means responsive to variations in load on the plant for varying the quantity of motive fluid supplied by said compressorand for positively varying the effective delivery stroke of each of said pumps by a separate` predetermined amount y for each pump.

13. In a gas turbine plantof the continuous combustion type, a yplurality of turbines coupled in series, at least one compressor driven by at least one of said turbines and arranged to profduce a variable quantity of motive fluid, a plurality of combustion chambers arranged at least before part of said turbines, means for 'supply-I ing motive fiuidfrom said compressor to said combustion chambers and to said turbines, a plurality of independent positively metering fuel pumps for supplying fuel to the several combustion chambers, and governing means responsive to variations in the load on the plant for cutting out of the series' at least one of said' turbines and for varying by a separate predetermined amount the quantity of positively metered fuel delivered by different ones of said fuel pumps.

14g In a gas turbine plant ofthe continuous combustion 'type for marine propulsion, a plurality of turbines, 4at least one compressor driven by at least one of said turbines and arranged to produce a variable quantity of motive uid, a plurality of combustion chambers arranged at least before part of said turbines, means for supplying motive f luid from said compressor to-said combustion vchambers and to said turbines, a

. plurality of independent positively metering fuel ,pumps for supplying fuel to the several combustion chambers, and manually operable controldependent positively metering heat supply means for supplying fuel to'the several heating means,

controlling means responsive to the `load on the plant for independently` controlling said heat I supply means', and means responsive to the out- (let temperature of at least one of said turbines for, controlling the temperature of the motive fluid supplied thereto.

17. Inv a gas turbine kplant of the continuous combustionV type, at-least one useful power turbine, at vleastV one compressor turbine independent of the useful power turbine with respect to speed of operation, at least one compressor driven by said compressor turbine and arranged toproduce a variable quantity of motive fluid, means` for maintaining substantially constant the speed of said useful power turbine including a gov' ernor, a plurality of independent heating means arrangedat least before part of saidturbines,

j `means for supplying motive fluid from said coml ,combustion type, a plurality ,of turbines, com- Jindependently controlling pressor to said heating means and to said turbines, and a pluralityk of independent positively metering heat supply means for supplying independent variable quantities of heat to the several heating means.

18. In a gas turbine plant of the continuous pressor means driven by at least one of said turbines and arranged` to produce a quantity of `Vmotive fluid variable in response to variations in the load on the plant; a plurality of independent heating means arranged at least before part of said turbines, means for supplying motive uid from said compressor means to said' heating means and to said turbines,`a plurality of independent positively metering heat supply means for supplying fuel to ,fthe several heating means, means responsive to the load on the plant for said heat Ysupply means, and means for varying the capacity of said compressor means while maintaining substantially constant speed of operation thereof.

ling means for independently varying the amount 15. In a gas turbine plant of the continuous `combustion type, a plurality of turbines, compressor means driven by at least one of said turbines and arranged to produce a quantity of motive fluid variable in response to variations in the loadon the plant, a plurality of independent heating means arranged at least before part of said turbines, means for supplying motive fluid `from said compressor means to 'said heating means andv to said turbines, a plurality of independent positively metering heat supply means for supplying fuel to theiseveral heating means, controlling means responsive to the, load on rthe plant for independently controlling said heat supply means, and means responsive to the lnlet temperature of at least one of said turbines for controlling the temperatureof the m'otive\ fluid supplied thereto. y

16. In a gas turbine plant of the continuous vcombustion type, a plurality of turbines, com- Y19. In a gas turbine plant of the continuous combustion type, a plurality of' turbines, `at least one compressor driven by at least one of said turbines and arranged ,to produce a variable quantity of compressed air, a plurality of gas generators arranged at least before part of said turbines, means for supplying compressed air from said compressor to said gas generators for producing motive fluid therein, means for supplying motive fluid from said gas generators to said turbines, a plurality of independent posi.

tively metering fuel supply means for supplyingV fuel to the several gas producers, and controlling means responsive to the load on the plant for `independently'controlling the 'rateof combustion in one of said gas generators.

20. In a gasfturbine plant Vof the continuous combustion type, a plurality ,of turbines, at least one compressor driven byi at least one of said 'turbines and arranged to produce a variable pressor means driven by at least one of said turl bines and arranged to produce aquantity of motive fluid variable in response `to variations in the load on the plant; a. plurality of independent heating means arranged at least before part of said turbines, means for supplying motive uld from said compressor means to said nheating quantity of compressed air, aplurality of gas generators arranged atleast before part of said turbines, means for supplying compressed air from said compressor to said gas generators for producing motive fluid'therein, means for supplying motive fluid from said gas generators to said turbines, a lplurality of independent posi-f' tively metering fuel supply means for supplying fuel to` the several gas producers, andu controlling means responsive to the temperature of saidV motive fluid for independently controlling the rate of combustion in one of said gas generators.

21. In a gas turbine plant of the 'continuous combustion type, a plurality of turbines, at least y one compressor driven by at least one .ot vsaid turbines and arranged to produce a variable quantity of compressed air, a plurality of gas generators arranged at least before part of said turbines, means for Vsupplying compressed air from said compressor to said gas generators for l0 producing motive fluid therein, means for supplying motive uid from said gas generators to said turbines, a plurality of independent positively metering fuel supply means for supplying fuel to the several gas producers, and means for independently controlling the quantity of fuel supplied to said gas generators, and the quantity of air supplied to said gas generators.

ALF LYSHOIM 

